2^8 Force, Energy, and Will 



0" 



Now of course it is impossible to ' mentally visualise ' th;it 

 which the eye has never seen — but is the invisible necessarily 

 incredible ? Professor Tyndall's own discoveries make it im- 

 possible for him to affirm such a proposition. It is conceded 

 on all hands that we cannot by imagination transcend experi- 

 ence, and we have experience of ' souls ' only in the energies 

 of ' living bodies ' ; but is that any reason for disbelieving in 

 them ? This question brings us to that of the ultimate 

 ground of all knowledge, and to the Professor's assertion, 

 that the hypothesis of a soul is an explanation of ' the un- 

 Imown in terms of the more unknown.' But far from this, 

 the explanation is in terms of the most known of all, for we 

 know nothing external so certainly as we know our own per- 

 sonal existence. Though no knowledge is possible to us 

 except as following upon sensation, yet the ground of all 

 developed knowledge is not sensational but intellectual — it 

 reposes ultimately not on ' feeling ' but on thoughts.^ Even 

 in verification by sensation it is the intellect which doubts, 

 criticises, and judges the actions and suggestions of the 

 senses and imagination ; and if we have (as I am confident 

 we have) rational grounds for adopting such a purely intel- 

 lectual conception as that of the human soul, the poverty of 

 our powers of imagination should be no bar to its acceptance. 

 We are continually employing conceptions of the kind — such. 

 e.g., as number, being, substance, cause, etc. — conceptions per- 

 fectly intelligible though transcending the powers of the ima- 

 gination. The utterly unimaginable may be the most supreme 

 of certainties, and what in its nature is necessarily undemon- 

 strable to sense, need be none the less clear on that account 

 to the eye of the intellect. To that same eye is alone visible 

 our own continued personal existence and identity, which 

 is vouched for by higher evidence than that of sensation. 



Such is Professor Tyndall's argument against the exist- 



1 See ante, p. 218. 



